The overall objective of this proposal is to investigate methods which can be used to develop and integrate several desirable core components of electronic medical record systems (EMRS) into functional EMRS applications through the use of wide-area network services and component- based software. The services and components proposed cover the areas of common clinical vocabularies, links to knowledge resources, and data sharing methods. Particular attention to the interface of these network- based services to the client application is given, and a component-based software services architecture is explored. All methods proposed will be tested in operational EMRS applications through the Laboratory's implementation of the Clinical Workstation (CWS) at the Massachusetts General Hospital (MGH) and the Brigham and Women's Hospital (BWH) integrated EMRS. To promote shareability and reusability of these components, all methods and their corresponding services will be made available through application programming interfaces and component-based software modules for use by collaborating research institutions over wide-area networks.